public Block(long index, ProofOfWork proof, Sha256Hash previousHash, IEnumerable <Transaction> transactions, long?timestamp = null)
{
if (index <= 0)
{
throw new ArgumentException("Index must be greater than zero");
}
if (proof == null)
{
throw new ArgumentNullException("Proof must not be null");
}
if (previousHash == null)
{
throw new ArgumentNullException("PreviousHash must not be null");
}
if (timestamp.HasValue && timestamp.Value <= 0)
{
throw new ArgumentException("Timestamp must be greater than zero");
}
// Blocks without transactions are adding new layers of difficulty to ensure the
// practical immutability of past blocks, i.e. the list of transactions may be empty
this.index = index;
this.timestamp = timestamp ?? DateTimeOffset.UtcNow.ToUnixTimeSeconds();
this.proof = proof;
this.previousHash = previousHash;
this.transactions = transactions.ToList();
}
private Block()
{
this.index = 1;
this.timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
this.proof = new ProofOfWork(1);
this.previousHash = Sha256Hash.Of("Genesis");
this.transactions = new List <Transaction>();
}
public virtual bool Verify(ProofOfWork lastProof)
{
if (lastProof == null)
{
throw new InvalidOperationException("Last proof must not be null");
}
return(Sha256Hash
.Of($"{lastProof.Value}{Value}")
.StartsWith("0000"));
}
/// <summary>
/// Create a new block in the blockchain
/// </summary>
private Block NewBlock(ProofOfWork proof)
{
var block = new Block(
index: chain.Count + 1,
proof: proof,
previousHash: LastBlock.Hash(),
transactions: currentTransactions);
currentTransactions.Clear();
chain.Add(block);
DomainEvents.Raise(new NewBlockForgedEvent());
return(block);
}